The over-arching aim of this proposal is to provide policy-relevant findings on the need, unmet need, use, costs, and outcomes of children's mental health services that have direct implications for organizing and financing national health care policies for children, particularly for ethnic minority children in diverse urban areas. Los Angeles (LA) is an important site to include in any national discussion of children's health policies: it represents 1 of 30 children in the country; 1 of 10 children in child welfare; has 73% Asian-, Latino-, and African-American children; has experienced community stressors (earthquakes, riots, fires) associated with mental health problems; offers several, diverse alternative candidate communities; and CA operates under a managed health care system, foreshadowing the national trend. This study proposes to examine ethnically diverse communities, North Long Beach and Compton in LA and Oxnard in Ventura County. While differing along many dimensions, Oxnard will have higher levels of service integration than any LA community and an organization of care that has stopped rising costs for mental health care. We will contrast the systems of care in these communities with case studies, identify positive and negative models of care, and document how children's need, access, and utilization of mental health services varies with family and community factors. To address these questions, 2000 children aged 4-17 years will be recruited from random household surveys in each community (800 expected to be at High Risk; 1200 at Low Risk). Because services that are not labeled mental health care often address children's adjustment problems, we will also randomly sample children in contact with at least one service sector in the same communities (n=750/community, Service Sector Sample from mental health; primary health care providers; special education; juvenile justice; substance abuse; foster care; & Head Start). It is anticipated that the family's access to services through the public sector, health maintenance organizations (HMOs), or fee-for-service (FFS), will dramatically influence the quantity, type, appropriateness, and process of care; therefore, we will sample-from each of these systems. By assessing the process of care, costs, and monitoring the child's developmental, functional, and clinical outcomes over two years, we will examine: l) whether communities investment of fiends in the children with the highest need is the most cost-effective strategy (i.e., examining the relative balance among child outcomes, costs, and cost-effectiveness); 2) whether those who are high utilizers of service have better outcomes than those not receiving services; 3) whether those who have received services rated as appropriate or integrated have better outcomes than those who have not; 4) identify the likely pathways through service sectors for children with different types of mental health problems; 5) identify positive and negative developmental-, ethnic-, and gender-linked trajectories for children with varying types of risk factors and mental health problems; and 6) describe the economic and psychological burden families experience when their child has mental health problems.